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Endless Fresh Water At Sea By Dehumidifiers
Fri, 08/01/2008 - 22:45 — TheSwager
the ocean in the sunlight can get quite humid as water evaporates in order to get large amounts of drinking water at sea Dehumidifiers can be employed
they suck humidity out of the air and turn it into water, they are cheap and could be easily used on a seastead
en.wikipedia.org/wiki/Dehumidifier
http://en.wikipedia.org/wiki/Atmospheric_water_generator
there is a developing technology based on this dehumidifier called an Atmospheric water generator they are made for the specific purpose of creating fresh water from the air
this seems more energy efficient then desalination because these can be powered by a local solar panel.
following from wikipedia (
Cost Details
The following is the cost per liter calculation for a typical 120 litres per day AWG with power consumption 2.6kW @ INR(Indian Rupee) 4.5 per kWh.
The cost of producing 1 liter of water will typically range from $US0.03 (85-100% RH) to $US0.06 (40-50% RH).
Total annual electric costs : 2.6kW × 24 hrs/day × 365 days/year ×INR 4.5 per kWh = Rs.1,02,492/year ≈ US$2,277.60/year (US$1 = INR45).......A
Total annual water production : 120 litres per day × 365 days/year = 43,800litres/year..........B
COST PER LITER = A ÷ B = US$0.05
NB the above calculation is suspect because it does not include the capital cost of the equipment, typically $1400.)
Looks good...
We may just have a potable water winner here.
Powerless dehumidifier works, too
You can make use of just the night/day temperature and air pressure cycle to power a very simple dehumidifier, too, and basically get your water for free (save for the capital cost), though it requires a lot more exchange and collection surface because of the much lower power rating.
Just a question...
You know you could use solar-thermal power to distill water for free, and harvest sea-salt at the same time? I assume there is some reason this idea has already been discarded, but I can't think off-hand what it might be.
It´s not free. Gathering
It´s not free. Gathering solar energy takes a lot of area, that otherwise can be used for other purposes. And then there is the equipment costs. Things cost money initially, and eventually they must be renewed, whether because of old age or just normal wear and tear, or accidents.
Now, it still might be cheaper than other ways, but not free. I tend to think that using your existing main energy source, whatever that is, to power some water machine will be the most efficient way to produce water in the long run. In the end it is essentially about exchanging energy for water. So, using the cheapest energy with the most efficient water making method will produce the cheapest water.